JP2005190794A - High-pressure discharge lamp and lighting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp having a highly reliable sealing part with high withstand pressure, capable of securing luminous efficiency and utilization efficiency of light and suitable for a device to magnify and project an image, and a lighting system using it. <P>SOLUTION: This high-pressure discharge lamp includes a fire resistant and translucent airtight container 1 provided with an enclosing part 1a having a discharge space 1a1 formed in its inside and a pair of sealing parts 1b, 1c extending from its both ends and having an outer diameter of D; a pair of electrodes 2, 2 sealed in the airtight container 1 while having an axial electrode diameter of d; and a discharge medium which is sealed in the discharge space 1a1 while containing mercury, halogen, and noble gas, and the mercury vapor pressure of which becomes at least 10 MPa when it is lighted, and satisfies 0.060 < d/D < 0.085. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a high-pressure discharge lamp that generates visible light by ultra-high pressure mercury vapor discharge and an illumination device using the same.

  In an apparatus for enlarging and projecting an image such as a liquid crystal projector or an overhead projector, a high-pressure discharge lamp is employed as the light source. Among these apparatuses, a liquid crystal projector is an apparatus that can project a moving image as well as a still image. Since various images can be projected by inputting a video signal or an image signal of a personal computer, it is used in various fields such as a presentation tool, a theater, or a large screen television.

  In such an apparatus, the light source is required to be close to a point light source and have a long lifetime. In response to this demand, high-pressure discharge lamps that generate visible light by ultrahigh-pressure mercury vapor discharge are widely used as contributing. As this high-pressure discharge lamp, a high-pressure discharge lamp in which the vapor pressure of mercury is set to an ultrahigh pressure of 200 bar (about 200 atmospheres) and halogen is enclosed is known (for example, see Patent Document 1). This high-pressure discharge lamp can suppress blackening caused by encapsulated halogen evaporating tungsten forming the electrode due to the electrode temperature at the time of lighting and solidifying on the inner wall surface of the translucent discharge vessel. It is stated. In addition, Patent Document 1 also describes that by encapsulating a metal halide having a lighting spectrum in the wavelength range of 580 to 780 nm, the red component is increased and light emission excellent in color rendering can be obtained.

In addition, regarding the improvement of the lifetime of a high-pressure discharge lamp that generates visible light by the above-described ultrahigh-pressure mercury vapor discharge, it is known that the illuminance maintenance rate of screen illuminance is excellent by enclosing an appropriate amount of halogen (for example, , See Patent Document 2). Furthermore, as for the halide to be sealed, sealing with CH ₂ Br ₂ gas is known (see Patent Document 3).

Further, in this type of high-pressure discharge lamp, the hermetic vessel is made of quartz glass and has a pair of sealing portions at both ends thereof. Inside the sealing portion, a sealing metal foil is embedded in an airtight manner, and an electrode and an external introduction conductor are connected via the sealing metal foil. And the sealing part is comprised so that the proof pressure may be raised by forming by pressure reduction sealing.
Japanese Patent No. 2829339 Japanese Patent Laid-Open No. 06-052830 Japanese Patent Laid-Open No. 08-245840

  However, this type of high-pressure discharge lamp is required to have a higher withstand pressure at the sealing portion, higher reliability, and ensure light emission efficiency and light utilization efficiency.

  However, this type of conventional high-pressure discharge lamp cannot sufficiently satisfy the above requirements.

  The present invention relates to a high-pressure discharge lamp suitable for use in an apparatus for enlarging and projecting an image that has a high withstand voltage of a sealing portion and is highly reliable, and can ensure light emission efficiency and light use efficiency, and illumination using the same An object is to provide an apparatus.

    A high-pressure discharge lamp according to claim 1 is a fire-resistant and light-transmitting hermetic container including an enclosing portion in which a discharge space is formed and a pair of sealing portions having an outer diameter D extending from both ends thereof; A pair of electrodes having an electrode shaft diameter d of 0.25 to 0.5 mm sealed in the hermetic vessel; and enclosed in the discharge space of the hermetic vessel containing mercury, halogen and rare gas, and mercury at the time of lighting A discharge medium having a vapor pressure of at least 10 MPa, and satisfying 0.060 <d / D <0.085.

  Since the high-pressure discharge lamp of the present invention has the above-described configuration, the physical strength of the enclosure portion in the ultrahigh pressure inside the vacuum vessel is maintained by suppressing the decrease in the coldest temperature of the light-emitting portion. The light can be emitted in a state. For this reason, the pressure resistance of the sealing portion is increased, and the reliability thereof is increased. The occurrence rate of breakage of the hermetic container is remarkably reduced, and high luminous efficiency is obtained. In addition, if it is within the above range of the present invention, the outer diameter of the sealing portion does not become larger than necessary, which is advantageous when condensing a high-pressure discharge lamp in combination with a reflecting mirror. In other words, since the degree to which the light that is generated by the discharge and should be incident on the reflecting mirror is kicked and blocked by the sealing portion is reduced, the required light utilization efficiency can be ensured.

  If the ratio d / D of the outer diameter D of the electrode shaft diameter d to the outer diameter D of the sealing portion is 0.085 or less, the occurrence rate of breakage of the hermetic container is significantly reduced. In addition, when the ratio d / D is less than 0.060, the withstand voltage is good, but the displacement of the electrode axis becomes large, and as a result, the screen illuminance is too low. On the other hand, when the ratio d / D exceeds 0.085, the breakage rate is remarkably increased. Therefore, the object of the present invention can be achieved by satisfying the condition of 0.060 <d / D <0.085 together with other conditions.

  The electrode shaft diameter d is limited to 0.25 to 0.5 mm because the electrode shaft diameter cannot be increased more than necessary to achieve the above object of the present invention. This is because processing problems also occur.

  Furthermore, the point that the mercury vapor pressure during lighting is at least 10 MPa or more is a precondition for this type of high-pressure discharge lamp.

    According to a second aspect of the present invention, there is provided an illuminating device comprising: an illuminating device main body; and the high-pressure discharge lamp according to the first aspect disposed in the illuminating device main body.

  According to the present invention, the high-pressure discharge lamp has a high pressure resistance of the sealing portion, and the reliability thereof is high, and high luminous efficiency and required light utilization efficiency can be ensured. The same effect can be obtained also in the lighting device. The illumination device is a broad concept including all devices that utilize the light emission of a high-pressure discharge lamp, and therefore, a light projection device such as a liquid crystal projector or an overhead projector, an automotive headlamp, a lighting fixture, a display device, and optical fiber illumination. Allow it to be a device. Of course, the lighting apparatus may be for indoor use or for outdoor use.

    According to the first aspect of the present invention, it is possible to provide a high-pressure discharge lamp in which the sealing portion has a high withstand voltage and has high reliability, and also ensures high light emission efficiency and required light utilization efficiency.

    According to the second aspect of the present invention, it is possible to provide an illuminating device having the effect of the first aspect and particularly suitable for a projector such as a liquid crystal projector.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

    FIG. 1 is a front view showing a first embodiment for carrying out the high-pressure discharge lamp of the present invention. In each figure, 1 is an airtight container, 2 is a pair of electrodes, 3 is a sealing metal foil, 4 is an introduction conductor, 5 is a base, and 6 is a connection conductor. Inside the hermetic vessel 1, a discharge medium is enclosed. In the present invention, the lamp power during stable lighting of the high-pressure discharge lamp can be set within a range of 30 to 200 W. In addition, a high-pressure discharge lamp suitable for various lighting devices may have a lamp power during stable lighting within the above range. However, the high-pressure discharge lamp of the present invention is particularly suitable for an image display apparatus that enlarges and projects an image such as a liquid crystal projector. In this case, the range of 80 to 180 W is suitable.

  <Airtight container 1> The airtight container 1 is fire-resistant and translucent, and is made of, for example, quartz glass, and includes a central surrounding portion 1a and first and second sealing portions 1b and 1c at both ends. The surrounding portion 1a has a spheroid shape whose outer shape is almost a sphere, for example, but the inside is a sphere or an ellipsoid, and has a long and narrow spheroid shape that is long in the tube axis direction, for example. A space 1a1 is formed.

  The first and second sealing portions 1b and 1c have an outer diameter of D (mm) and are integrally connected to both ends of the surrounding portion 1a by a reduced pressure sealing structure. The outer diameter D is an average value of the outer diameters of the sealing portions. And the magnitude | size is prescribed | regulated in ratio d / D mentioned later about the outer diameter D (mm) of a sealing part.

  <Electrode 2> The electrode 2 has a diameter d (mm) of 0.25 to 0.5 mm. It is allowed to have the electrode shaft 2a, the electrode main portion 2b, and the holding coil 2c as a general configuration. In the case of this configuration, the diameter of the electrode 2 is an average value of the electrode shaft 2a. The electrode shaft 2a is preferably made of a pure tungsten rod, and the base end is welded to a sealing metal foil 3 to be described later, the intermediate portion is loosely supported by the first and second sealing portions 1b and 1c, and The tip portion projects into the enclosure 1 a of the airtight container 1. The electrode main part 2b is formed by winding a pure tungsten wire twice around the tip of the electrode shaft 2a by dense winding several times. The holding coil 2c is disposed as desired in the present invention, and a pure tungsten thin wire is opposed to at least the first and second sealing portions 1b and 1c in the middle portion of the electrode shaft by a quartz glass holding portion. It is wound at an appropriate pitch on the part to be performed.

  <Sealing metal foil 3> When the airtight container 1 is made of quartz glass, the sealing metal foil 3 is suitable for introducing an electric current from the outside to the electrode 2 and sealing the airtight container 1 in an airtight manner. It is used as a means and is made of molybdenum foil. The sealing metal foil 3 is welded to the distal end of the electrode shaft 2a and the distal end of the introduction conductor 4 is welded to the proximal end to form electrode mounts. The first and second sealing portions 1b and 1c are embedded in an airtight manner.

  <Discharge medium> A discharge medium consists of mercury, a noble gas, and a halogen.

Mercury acts as a so-called luminescent metal that emits visible light by emitting light by discharge, and a required amount is enclosed so that the mercury vapor pressure is at least 10 MPa, preferably 15 MPa or more during stable lighting. Specifically, about 0.2 to 0.30 mg per unit internal volume (1 mm ³ ) of the airtight container 1 can be sealed. If the amount of mercury enclosed is within the above range, the red component during light emission increases and the color rendering is improved. Moreover, the bursting during lighting of the airtight container 1 can be suppressed.

  The noble gas acts as a starting gas and a buffer gas, and can be encapsulated in one kind such as argon (Ar), krypton (Kr), and xenon (Xe) alone or in a mixture of plural kinds.

Generally, halogen can be enclosed within a range of 1.0 × 10 ^{−4 to} 5.0 × 10 ⁻⁴ μmol / mm ³ per unit internal volume of the discharge space 1a1 of the hermetic vessel 1, and preferably Is around 2.0 × 10 ⁻⁴ μmol / mm ³ . Further, the halogen is composed of one or more halides of iodine (I), bromine (Br), and chlorine (Cl), for example, CH ₂ Br ₂ or the like, or a halogen simple substance. Thus, the enclosed halogen exhibits a halogen cycle action in the hermetic container 1, and as a result, blackening due to damage to the electrode and scattering of tungsten as the electrode material is suppressed, and the high-pressure discharge lamp has a long life. .

  <Introduction conductor 4> The introduction conductor 4 is made of molybdenum (Mo) wire, the distal end is welded to the proximal end of the sealing metal foil 3, and the proximal end is exposed to the outside from the first sealing portion 1b. The introduction conductor 4 has a symmetrical structure in the figure, but the right introduction conductor is not visible from the outside because it is located in a base 5 described later.

  <Base 5> The base 5 includes a cylindrical base body 5 a and a screw terminal 5 b. The base body 5a is made of a metal such as brass, and one end portion thereof is fixed to the end portion of the first sealing portion 1b by a base cement, that is, an inorganic adhesive. The screw terminal 5b has a thread groove formed in the outer periphery, is formed integrally with the base body 5a, protrudes outward along the tube axis from the center portion of the base body 5a, and is formed at the center portion thereof. The introduction conductor is inserted into the through hole and connected to the introduction conductor by welding. And the screw terminal 5b contributes to supplying electric power by fixing a high-pressure discharge lamp in a predetermined position by screwing a lamp plug (not shown) into the predetermined position and connecting it to one output terminal of the lighting circuit. be able to.

  <Connection conductor 6> The front end of the connection conductor 6 is welded to the introduction conductor 4 whose front end protrudes to the outside from the second sealing portion 1c. Then, the other output terminal of the lighting circuit can be connected via the connection conductor 6 to contribute to feeding.

Discharge vessel 1: Quartz glass, maximum outer diameter 9.0 mm, maximum inner diameter 4.0 mm,
An internal volume of 50 mm ³ , a diameter of the first and second sealing portions 5.6 mm,
Length 21mm, sealing metal sealing length 17mm
Electrode 1b: Pure tungsten wire with a diameter of 0.4 mm, coil wire diameter of electrode main part
0.15mm, distance between electrodes 1.3mm, wire diameter of holding coil
0.075mm, pitch 150%
Discharge medium Mercury: 11.5mg
Halogen: 1.0 μg
Noble gas: Ar 0.15 atm Lamp voltage: 80V
Lamp power: 100W

Next, with reference to FIG. 2 and FIG. 3, in the high-pressure discharge lamp having the configuration shown in FIG. The results will be explained.

  FIG. 2 shows that the same high-pressure discharge lamps as those shown in FIG. 1 were manufactured except that the ratio d / D was changed, and the ratio d / D and the burst occurrence rate (%) within 100 hours of lighting. It is the graph which showed this relationship. As can be understood from FIG. 2, when the ratio d / D is 0.085 or less, the burst occurrence rate is 1% or less, and there is no practical problem. However, when the ratio d / D exceeds 0.085, the breakage occurrence rate starts to increase rapidly. When the ratio d / D is 0.09 or more, the breakage rate rapidly increases to 5% or more.

FIG. 3 shows the same high pressure discharge lamp as that shown in FIG. 1 except that the ratio d / D is changed, as in FIG. 2, and shows the relationship between the ratio d / D and the relative value of screen illuminance. It is a graph. As can be understood from FIG. 3, the ratio d / D and the screen illuminance have a positive correlation that is almost proportional, but when the ratio d / D is less than 0.06, the screen illuminance is too low and practical. There is a problem above. However, if the ratio d / D is 0.06 or more, a characteristic with a screen illuminance relative value of 0.95 or more is obtained, and there is no significant decrease in illuminance.
It turns out that there is no problem in practical use.

  As described above, as can be understood from FIG. 2 and FIG. 3, if the ratio d / D is in the range of 0.06 to 0.085, the occurrence rate of breakage of the hermetic container is low and the screen illuminance is high. It can be seen that a high pressure discharge lamp is obtained.

    FIG. 4 is a partial cross-sectional front view showing a second embodiment for carrying out the high-pressure discharge lamp of the present invention. This embodiment is different in that a concave reflecting mirror is integrally provided. Note that the same parts as those in FIG. In the figure, 11 is a high-pressure discharge lamp, 12 is a concave reflector, 13 is an inorganic adhesive, 14 is a relay terminal, 15 is a wire harness, and 16 is a front cover.

  The high-pressure discharge lamp 11 has the same structure as shown in FIG.

  The concave reflecting mirror 12 includes a glass base 12a having an inner surface that is concave, a visible light reflecting / heat ray transmitting film 12b, and a cylindrical portion 12c. The glass base 12a is formed such that the concave portion on the inner surface is a curved surface based on a paraboloid of revolution, and the cylindrical portion 12c is integrally projected on the outer side of the top. The visible light reflection / heat ray transmission film 12b is formed of a dichroic reflection film.

  In order to attach the high-pressure discharge lamp 11 to the concave reflector 12, the base 5 is inserted into the cylindrical portion 12c, the light emission center of the high-pressure discharge lamp 11 is made to coincide with the focal point of the concave reflector 12, and the base 5 and the cylindrical shape. Both are fixed by interposing an inorganic adhesive 13 between the portion 12c.

  A connection conductor 6 is welded to the introduction conductor 4 on the one electrode 2 side of the high-pressure discharge lamp 11 and led out to the back side of the concave reflecting mirror 12. That is, the connecting conductor 6 is led out to the back side of the concave reflecting mirror 12 through a through hole 12d formed in a part of the mirror surface.

  The relay terminal 14 is fixed in the vicinity of the through hole 12 d on the outer surface of the concave reflecting mirror 12. The connection between the connection conductor 6 connected to the high-pressure discharge lamp 11 and the wire harness 15 is relayed.

  The wire harness 15 includes a connector 15a and a pair of insulating coated conductors 15b and 15c. The connector 15 is detachably coupled to and connected to a connector at the output end of the lighting device (not shown), and is connected to one end of the insulation coated conductors 15b and 15c. The other end of the insulating coated conductor 15 b is connected to the relay terminal 14. The other end of the insulating coated conductor 15c is connected to the screw terminal 5b of the base 5 by being tightened by a knurled nut 5c.

  The front cover 16 is made of a transparent glass plate and is bonded to the front opening end of the concave reflecting mirror 12.

  Then, when the connector 15a of the wire harness 15 is connected to the lighting device and the high pressure discharge lamp 11 is turned on, the light beam generated from the high pressure discharge lamp 11 is reflected by the visible light reflection / heat ray reflection film 12b of the concave reflector 12. The visible light is reflected and emitted parallel to the optical axis, passes through the front cover 16 and is used for illumination. On the other hand, heat rays pass through the visible light reflecting / heat ray transmitting film 12b, and further pass through the glass substrate 12a and are diffused to the back side of the concave reflecting mirror 12, thereby suppressing an increase in temperature of the liquid crystal display or the like. can do.

    FIG. 5 is a conceptual cross-sectional view showing a liquid crystal projector as an embodiment for carrying out the illumination device of the present invention. In the figure, 21 is a high pressure discharge lamp, 22 is a liquid crystal display means, 23 is an image control means, 24 is an optical system, 25 is a high pressure discharge lamp lighting device, 26 is a main body case, and 27 is a screen.

  The high-pressure discharge lamp 21 is the same as that of the second embodiment for carrying out the present invention shown in FIG.

  The liquid crystal display means 22 displays an image to be projected by liquid crystal, and is illuminated by the high-pressure discharge lamp device 21 from the back.

  The image control means 23 drives and controls the liquid crystal display means 22, and can be provided with a television reception function if necessary.

  The optical system 24 projects the light that has passed through the liquid crystal display means 22 onto the screen 27.

  The high pressure discharge lamp lighting device 25 lights the high pressure discharge lamp 21.

  The main body case 26 accommodates the above elements 21 to 26.

The front view which shows the 1st form for implementing the high pressure discharge lamp of this invention 100 high-pressure discharge lamps are manufactured in the same manner as shown in FIG. 1 except that the ratio d / D is changed, and the relationship between the ratio d / D and the burst occurrence rate (%) within 100 hours of lighting is shown. Graph A graph showing the relationship between the ratio d / D and the relative value of screen illuminance for the same high-pressure discharge lamp as that shown in FIG. 1 except that the ratio d / D was changed. The partial cross section front view which shows the 2nd form for implementing the high pressure discharge lamp of this invention 1 is a conceptual cross-sectional view showing a liquid crystal display device as an embodiment for carrying out the illumination device of the present invention

Explanation of symbols

      DESCRIPTION OF SYMBOLS 1 ... Airtight container, 1a ... enclosure part, 1a1 ... discharge space, 1b ... 1st sealing part, 1c ... 2nd sealing part, 2 ... electrode, 2a ... electrode axis, 2b ... electrode main part, 3 ... Sealing metal foil, 4 ... Introducing conductor, 5 ... Base, 5a ... Base body, 5b ... Screw terminal, 6 ... Connection conductor

Claims (2)

A fire-resistant and light-transmitting hermetic container having an enclosure portion in which a discharge space is formed and a pair of sealing portions having an outer diameter D extending from both ends thereof;
A pair of electrodes having an electrode shaft diameter d of 0.25 to 0.5 mm sealed in an airtight container;
A discharge medium containing mercury, halogen and a rare gas, enclosed in a discharge space of an airtight container, and having a mercury vapor pressure of at least 10 MPa at the time of lighting;
The high pressure discharge lamp is characterized by satisfying 0.060 <d / D <0.085. A lighting device body;
The high-pressure discharge lamp according to claim 1 disposed in the illuminating device body;
An illumination device comprising:

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